Determination of aconitum alkaloids in acute poisoning case by electromembrane extraction.

In this work, electromembrane extraction (EME) was used for the first time to separate aconitine (AC), mesaconitine (Mes-AC) and hypaconitine (Hyp-AC) from biological samples and Chinese herbal medicines. Efficient EME of polar and high molecular weight aconitine alkaloids from different sample matrices was achieved with the solvent of 1-ethyl-2-nitrobenzene (ENB). Under the optimal EME conditions, EME provided recoveries for all targets in the range of 72%-74 %, 85%-103 % and 92%-94 % for whole blood, urine and aqueous samples. The proposed EME systems combined with LC-MS/MS and HPLC-UV were evaluated using different sample matrices, and the methods displayed satisfactory analytical characteristic including negligible matrix effect. The LOD and LOQ of AC, Mes-AC, and Hyp-AC by EME-LC-MS/MS were in the range of 0.002-0.068 ng/mL and 0.005-0.228 ng/mL respectively. The LOD and LOQ of AC, Mes-AC, and Hyp-AC by EME-HPLC-UV were in the range of 0.06-0.26 µg/mL and 0.20-0.86 µg/mL, respectively. The coefficient of determination, R2-value was ≥0.9926 for all cases, and the accuracy in the linear ranges was in the range of 91%-111 %. Finally, the method was successfully applied for the qualitative and quantitative analysis of AC and Mes-AC in the whole blood and herbal medicine dreg samples from an actual forensic case, and poisoning by aconitum alkaloids was identified as the cause of death. Therefore, we believe that EME could be a powerful tool to identify poisoning, and EME has great potential for efficient separation of polar and high molecular weight substances. These are of great importance in the fields of but not limited to forensic science, Traditional Chinese Medicine and clinics.

Postmortem Diffusion of Aconitum Alkaloids and Their Metabolites in Rabbits.

OBJECTIVES: To explore the postmortem diffusion rule of Aconitum alkaloids and their metabolites in poisoned rabbits, and to provide a reference for identifying the antemortem poisoning or postmortem poisoning of Aconitum alkaloids. METHODS: Twenty-four rabbits were sacrificed by tracheal clamps. After 1 hour, the rabbits were administered with aconitine LD50 in decocting aconite root powder by intragastric administration. Then, they were placed supine and stored at 25 ℃. The biological samples from 3 randomly selected rabbits were collected including heart blood, peripheral blood, urine, heart, liver, spleen, lung and kidney tissues at 0 h, 4 h, 8 h, 12 h, 24 h, 48 h, 72 h and 96 h after intragastric administration, respectively. Aconitum alkaloids and their metabolites in the biological samples were analyzed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). RESULTS: At 4 h after intragastric administration, Aconitum alkaloids and their metabolites could be detected in heart blood, peripheral blood and major organs, and the contents of them changed dynamically with the preservation time. The contents of Aconitum alkaloids and their metabolites were higher in the spleen, liver and lung, especially in the spleen which was closer to the stomach. The average mass fraction of benzoylmesaconine metabolized in rabbit spleen was the highest at 48 h after intragastric administration. In contrast, the contents of Aconitum alkaloids and their metabolites in kidney were all lower. Aconitum alkaloids and their metabolites were not detected in urine. CONCLUSIONS: Aconitum alkaloids and their metabolites have postmortem diffusion in poisoned rabbits, diffusing from high-content organs (stomach) to other major organs and tissues as well as the heart blood. The main mechanism is the dispersion along the concentration gradient, while urine is not affected by postmortem diffusion, which can be used as the basis for the identification of antemortem and postmortem Aconitum alkaloids poisoning.

The Metabolic Pathways and Products of Ten Aconitum Alkaloids in Sanwujiao Pills from Eight Organs of Mice by UHPLC-Q-TOF-MS/MS.

BACKGROUND: Sanwujiao pill (SWJP) is a Chinese herbal preparation widely used in China. It is an essential medicine for treating rheumatism and blood stasis. However, its safety in clinical use has always been the focus of patients because it contains toxic herbs of Aconitum carmichaelii Debx. and A. vilmorinianum Kom. OBJECTIVE: To further reveal the pharmaceutical and toxic effect substances and the action mechanism of SWJPs, the metabolites and their pathways of ten Aconitum alkaloids (AAs) in the preparation at different time points after oral administration in eight organs of mice were investigated. METHOD: The biosamples were investigated by a four-step strategy of UPLC-Q-TOF-MS /MS technology. RESULTS: Aconitine (AC), mesaconitine (MA), and hypaconitine (HA) were not detected in any organs. The highest concentrations of the other seven AAs occurred at 0.5 h. Yunaconitine (YAC) was not detected in the brain; all seven AAs had the lowest concentration in the brain, and the metabolism was slow in the stomach. Twelve predicted metabolites were identified, the kidney and stomach were their primary distribution locations, and the most metabolites were found at 0.5h. The main metabolic pathways of the ten AAs were demethylation, deethylation, deoxygenation, hydroxylation, and deacetylation. CONCLUSION: This is the first report about the metabolism of ten AAs in SWJPs in mice. Significantly, the metabolic pathways and products of four hidden toxic AAs were analyzed in vivo for the first time. The results were of great significance for the safety and effectiveness of SWJPs in clinical application.

Neoline, fuziline, songorine and 10-OH mesaconitine are potential quality markers of Fuzi: In vitro and in vivo explorations as well as pharmacokinetics, efficacy and toxicity evaluations.

ETHNOPHARMACOLOGICAL RELEVANCE: Fuzi, the lateral roots of Aconitum carmichaelii Debx, plays an irreplaceable role in treating Yang deficiency and cold coagulation syndromes. However, Fuzi has a narrow margin of safety since its pharmacological constituents, Aconitum alkaloids, have potential cardiotoxicity and neurotoxicity. The current quality markers (Q-markers) for the control of Fuzi's efficacy and toxicity are 3 monoester-diterpenoid alkaloids, namely, benzoylaconine (BAC), benzoylhypaconine and benzoylmesaconine (BMA) and 3 diester-diterpenoid alkaloids, namely, aconitine (AC), hypaconitine and mesaconitine (MA). However, mounting evidence indicates that the current 6 Q-markers may not be efficacy- or toxicity-specific enough for Fuzi. AIM OF THE STUDY: The aim of this study was to explore and evaluate efficacy- or toxicity-specific potential quality markers (PQ-markers) of Fuzi. MATERIALS AND METHODS: PQ-markers were explored by analyzing 30 medicinal samples and alkaloids exposed in mouse. Pharmacokinetics of PQ-markers on C57BL/6J mice were determined. Anti-inflammatory effects of PQ-markers were evaluated by λ-carrageenan-induced paw edema model and lipopolysaccharide-induced RAW264.7 cell inflammatory model, while analgesic effects were assessed by acetic acid-induced pain model and Hargreaves test. Cardiotoxicity and neurotoxicity of PQ-markers were assessed by histological and biochemical analyses, while acute toxicity was evaluated by modified Kirschner method. RESULTS: After in vitro and in vivo explorations, 7 PQ-markers, namely, neoline (NE), fuziline (FE), songorine (SE), 10-OH mesaconitine (10-OH MA), talatizamine, isotalatizidine and 16ß-OH cardiopetalline, were found. In the herbal medicines, NE, FE, SE and 10-OH MA were found in greater abundance than many other alkaloids. Specifically, the amounts of NE, FE and SE in the Fuzi samples were all far higher than that of BAC, and the contents of 10-OH MA in 56.67% of the samples were higher than that of AC. In mouse plasma and tissues, NE, FE, SE, talatizamine, isotalatizidine and 16ß-OH cardiopetalline had higher contents than the other alkaloids, including the 6 current Q-markers. The pharmacokinetics, efficacy and toxicity of NE, FE, SE and 10-OH MA were further evaluated. The average oral bioavailabilities of NE (63.82%), FE (18.14%) and SE (49.51%) were higher than that of BMA (3.05%). Additionally, NE, FE and SE produced dose-dependent anti-inflammatory and analgesic effects, and their actions were greater than those of BMA. Concurrently, the toxicities of NE, FE and SE were lower than those of BMA, since no cardiotoxicity or neurotoxicity was found in mice after NE, FE and SE treatment, while BMA treatment notably increased the creatine kinase activity and matrix metalloproteinase 9 level in mice. The average oral bioavailability of 10-OH MA (7.02%) was higher than that of MA (1.88%). The median lethal dose (LD50) of 10-OH MA in mice (0.11 mg/kg) after intravenous injection was close to that of MA (0.13 mg/kg). Moreover, 10-OH MA produced significant cardiotoxicity and neurotoxicity, and notable anti-inflammatory and analgesic effects that were comparable to those of MA. CONCLUSIONS: Seven PQ-markers of Fuzi were found after in vitro and in vivo explorations. Among them, NE, FE and SE were found to be more efficacy-specific than BMA, and 10-OH MA was as toxicity-specific as MA.

Targeted preparation and recognition mechanism of broad-spectrum antibody specific to Aconitum alkaloids based on molecular modeling and its application in immunoassay.

Ester-type Aconitum alkaloids (AAs), the main medicinal ingredients of Aconitum L. herbs, could cause brain and heart damage in humans and animals and have raised concerns worldwide. In the present study, we aimed to produce a high-performance and broad-spectrum antibody and establish an immunoassay method of ester-type AAs, 3-succinyl aconitine (ACO-HS) was selected as an optimal hapten from five designed haptens comparing the similarity of stereo structure, electronic distribution, and physicochemical properties using the computer-aided molecular modeling technology. The monoclonal antibody (mAb) 1A9 exhibited broad-spectrum recognition specificity of 15 ester-type AAs was obtained and had a high sensitivity with the binding affinity (half-maximum inhibition concentration, IC50) of 0.73-130.36 µg L-1. Through molecular docking, it was found that mAb 1A9 and ester-type AAs showed a semi-enveloped structure through hydrogen bonds and hydrophobicity interaction. The amino acid residues that responsible for recognition were ARG107, GLU55, PRO113, VAL36, and SER64, and the critical structures to be recognized of AAs were acetyl group, benzoyl group, and N-linked carbon chains. The developed indirect competitive enzyme-linked immunosorbent assay (icELISA) based on mAb 1A9 allowed a sensitive determination of 15 ester-type AAs with the limit of detection (LOD) of 0.21-43.72 µg L-1, and it was suitable for the analysis of ester-type AAs in various Aconitum L. samples. These results provided an effective strategy for the preparation of targeted broad-spectrum antibodies of small molecules and proposed an icELISA method available for rapid, sensitive, and high-throughput detection of toxic ester-type AAs in Aconitum L. herbs.

The effect of compatibility of Aconiti Radix and honey on the pharmacokinetics of five Aconitum alkaloids in rat plasma.

Aconiti Radix [Chuanwu (CW)] is widely used to treat chronic and intractable diseases due to its remarkable curative effect. CW has been combined with honey for thousands of years to reduce toxicity and enhance efficacy. This study first determined the compatibility mechanism of CW with honey using a comparative pharmacokinetic concept. We developed and validated a simple, sensitive, specific, and accurate UHPLC-MS/MS method to simultaneously determine five Aconitum alkaloids in rat plasma after the oral administration of CW decoction and CW-honey concentrated solution. Pharmacokinetic parameters were significantly different between the two groups (P < 0.01 and P < 0.05). Compared with the CW group, Cmax and AUC0 → t decreased in the CW-honey group for three diester-diterpenoid alkaloids (hypaconitine, mesaconitine, and aconitine); Tmax and T1/2 were prolonged. However, Cmax and AUC0 → t increased in the CW-honey group for two monoester-diterpenoid alkaloids (benzoylaconine and benzoylmesaconine); Tmax was shortened, and T1/2 was prolonged. These findings suggest that honey affected the pharmacokinetic behaviors of five Aconitum alkaloids. We speculate that the detoxification and synergism of honey might result from reducing the toxicity of diester-diterpenoid alkaloids and promoting the biological activity of monoester-diterpenoid alkaloids in vivo. This study provides a theoretical basis for the clinical use of CW combined with honey.

A systematic review of pharmacological activities, toxicological mechanisms and pharmacokinetic studies on Aconitum alkaloids.

The tubers and roots of Aconitum (Ranunculaceae) are widely used as heart medicine or analgesic agents for the treatment of coronary heart disease, chronic heart failure, rheumatoid arthritis and neuropathic pain since ancient times. As a type of natural products mainly extracted from Aconitum plants, Aconitum alkaloids have complex chemical structures and exert remarkable biological activity, which are mainly responsible for significant effects of Aconitum plants. The present review is to summarize the progress of the pharmacological, toxicological, and pharmacokinetic studies of Aconitum alkaloids, so as to provide evidence for better clinical application. Research data concerning pharmacological, toxicological and pharmacokinetic studies of Aconitum alkaloids were collected from different scientific databases (PubMed, CNKI, Google Scholar, Baidu Scholar, and Web of Science) using the phrase Aconitum alkaloids, as well as generic synonyms. Aconitum alkaloids are both bioactive compounds and toxic ingredients in Aconitum plants. They produce a wide range of pharmacological activities, including protecting the cardiovascular system, nervous system, and immune system and anti-cancer effects. Notably, Aconitum alkaloids also exert strong cardiac toxicity, neurotoxicity and liver toxicity, which are supported by clinical studies. Finally, pharmacokinetic studies indicated that cytochrome P450 proteins (CYPs) and efflux transporters (ETs) are closely related to the low bioavailability of Aconitum alkaloids and play an important role in their metabolism and detoxification in vivo.

Pharmacokinetics and tissue distribution of eighteen major alkaloids of Aconitum carmichaelii in rats by UHPLC-QQQ-MS.

Aconitum carmichaelii Debeaux is a widely used herbal medicine, which has anti-inflammatory and analgesic activities. However, due to its high toxicity, poisoning incidents often occur all over the world. To systematically understand the pharmacokinetics (PK) and tissue distribution of A. carmichaelii, 18 representative alkaloids, including 8 amine- (ADA), 4 monoester- (MDA) and 6 diester-type (DDA) diterpenoid alkaloids, were simultaneously quantified by ultra-high performance liquid chromatography-triple quadrupole mass spectrometry (UHPLC-QQQ-MS) with dynamic multiple reaction monitoring (MRM) mode. PK results suggested that benzoylmesaconine, mesaconitine, 10-OH-aconitine and aconitine had lower bioavailability, which might relate to the substitution at C-3. In tissue distribution, alkaloids present higher concentrations in the liver, kidney, and only songorine, neoline and benzoyldeoxyaconine were detected in the brain. Moreover, the concentrations of extremely toxic DDAs in high-dose group were much higher than that of low-dose group, indicating that these DDAs might be the main reason for the toxicity of Aconitum. The results also suggested that benzoyldeoxyaconine and deoxyaconitine should be determined for the quality control of A. carmichaelii due to their high concentrations in both herbal extract and tissues. The systematic investigation into these 18 representative alkaloids could basically illuminate the PK and distribution of A. carmichaelii in rats, and provide some information for clinical studies.

A proton-coupled organic cation antiporter is involved in the blood-brain barrier transport of Aconitum alkaloids.

ETHNOPHARMACOLOGICAL RELEVANCE: The herbs of Aconitum are the essential Traditional Chinese medicine and have played an indispensable role in many Asian countries for thousands of years to treat critical illnesses, and chronic, stubborn diseases. However, Aconitum may induce severe neurotoxicity and even death. So far the mechanism of Aconitum penetrating the blood-brain barrier (BBB) is still unclear. AIM OF THE STUDY: To determine whether influx transporters contribute to the brain uptake of the highly toxic alkaloids in Aconitum including aconitine (AC), mesaconitine (MA) and hypaconitine (HA). MATERIALS AND METHODS: The uptake of AC, MA and HA was characterized using in vitro hCMEC/D3 model and in situ mouse brain perfusion. In hCMEC/D3 cells, the effect of incubation temperature, time, initial drug concentration, energy (NaN3), extracellular and intracellular pH (FCCP and NH4Cl), the prototypical substrates/inhibitors of known organic cation transporting carriers and trans-stimulation (pre-incubating with pyrilamine and diphenhydramine) on the cellular uptake were studied. In addition, the effect of silencing OCTN1, OCTN2 and PMAT by specific siRNA was investigated. In mice, the contribution of the proton-coupled antiporter on the brain uptake of Aconitum was investigated by chemical inhibition. RESULTS: In hCMEC/D3 cells, AC, MA and HA were each taken up in a temperature-, time- and concentration-dependent manner, which were reduced by NaN3 and FCCP. Regulation of extracellular and intracellular pH as well as trans-stimulation studies showed that AC, MA and HA were transported by a proton-coupled antiporter expressed at the plasma membrane that could also transport pyrilamine and diphenhydramine. Each uptake was markedly inhibited by various cationic drugs, but insensitive to the prototypical substrates/inhibitors of identified organic cation transporting carriers, such as OCTs, PMAT, MATEs and OCTNs. In addition, silence of OCTN1, OCTN2 and PMAT had no significant inhibitory effect on the uptake of AC, MA and HA. In mice, the brain uptake of each alkaloid measured by in situ brain perfusion was suppressed by diphenhydramine when the transport capacity of P-gp/Bcrp at the BBB was chemically inhibited. CONCLUSIONS: A novel proton-coupled organic cation antiporter plays a predominant role in the blood to brain influx of AC, MA and HA at the BBB, and thus affect the safety of Aconitum species.

A systematic review of pharmacokinetic studies on herbal drug Fuzi: Implications for Fuzi as personalized medicine.

BACKGROUND: Fuzi, which is the processed lateral roots of Aconitum carmichaeli Debx. (Ranunculaceae), is a traditional herbal medicine that is well known for its excellent pharmacological effects and acute toxicity. Aconitum alkaloids are responsible for its pharmacological activity and toxicity. Although a large number of studies on Fuzi have been reported, no comprehensive review on its pharmacokinetics has yet been published. PURPOSE: This paper seeks to present a comprehensive review regarding the phytochemistry, pharmacokinetic features and toxicity of Fuzi. The regulation of drug-metabolizing enzymes (DMEs) and efflux transporters (ETs) by Fuzi is also concluded. Additionally, the use of Fuzi as a personalized medicine based on the bioavailability barrier (BB), which mainly comprises DMEs and ETs, is discussed. METHODS: All available information on Fuzi was collected by searching for key words in PubMed, ScienceDirect, CNKI, Google Scholar, Baidu Scholar, and Web of Science. RESULTS: Aconitum alkaloids, which mainly include diester-diterpene alkaloids (DDAs), monoester-diterpene alkaloids (MDAs) and unesterified-diterpene alkaloids (UDAs), could be detected after Fuzi ingestion in vivo. The Aconitum alkaloids are rapidly absorbed in the intestine and extensively distributed in the body. DMEs, especially CYP3A4/5, are responsible for various types of metabolic reactions of the Aconitum alkaloids. ETs, including P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2), and breast cancer resistance protein (BCRP), are involved in the efflux of the DDAs and MDAs. The kidney is the most important organ involved in the excretion of the Aconitum alkaloids. DDAs are the main toxic compounds present in Fuzi, and their acute toxicity is mainly due to their effects on the voltage-dependent sodium channels. Furthermore, Fuzi can substantially regulate DMEs and ETs. CONCLUSIONS: The toxicity of DDAs is acute. However, further investigations are necessary to determine the exact toxicological mechanisms. The significant impact of Fuzi on DMEs and ETs suggests that the co-administration of Fuzi with drugs that are substrates of DMEs and/or ETs may cause herb-drug interactions (HDIs). The BB network controlled exposure to the Aconitum alkaloids in vivo. Polymorphisms of DMEs and ETs in different individuals contribute to the differences in the efficacy and toxicity of Fuzi ingestion. In the future, the use of Fuzi as personalized medicine based on the BB network is necessary and practical to achieve ideal therapeutic efficacy with minimal toxicity.

Aconitum alkaloids, the major components of Aconitum species, affect expression of multidrug resistance-associated protein 2 and breast cancer resistance protein by activating the Nrf2-mediated signalling pathway.

BACKGROUND: Aconitum alkaloids from Aconitum species are often used to treat arthritis and rheumatic diseases but have the drawback of high toxicity. Identifying their pharmacokinetic behaviour is important for the safe clinical application of Aconitum species. Efflux transporters (ETs), including P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2), and breast cancer resistance protein (BCRP), have important functions in regulating the pharmacokinetic behaviours of drugs and in herb-herb or herb-drug interactions (HDIs). The Aconitum alkaloids regulate P-gp expression and function, but their effects on MRP2 and BCRP expression remain unknown. PURPOSE: To determine the effects of three Aconitum alkaloids, aconitine (AC), benzoylaconine (BAC), and aconine, on MRP2 and BCRP. METHODS: The levels of the protein and mRNA expression of MRP2 and BCRP in vivo and in vitro were measured via Western blotting and real-time PCR, respectively. Fluorescence signals of MRP2 and BCRP were detected via confocal fluorescence microscopy. A reporter assay using HepG2-C8 cells, which were generated by transfecting plasmids containing the antioxidant response element (ARE)-luciferin gene into HepG2 cells, was used to examine the ARE-luciferin activity. The transport activities of MRP2 and BCRP were tested via flow cytometry using substrate probes. RESULTS: The Aconitum alkaloids significantly up-regulated MRP2 and BCRP expression, accompanied by a marked increase in nuclear factor E2-related factor-2 (Nrf2) expression in the jejunum, ileum, and colon of FVB mice, in the order AC < BAC < aconine. In the in vitro model, the Aconitum alkaloids increased MRP2 and BCRP expression in Caco-2 and LS174T cells, in the order AC < BAC < aconine. Additionally, these alkaloids promoted the translocation of Nrf2 from the cytoplasm to the nucleus and significantly increased ARE-luciferin activity in HepG2-C8 cells. Luteolin, a potent inhibitor of Nrf2, markedly prevented MRP2 and BCRP expression from being induced by the three Aconitum alkaloids. The efflux activity of MRP2 was also significantly increased in cells receiving the same treatment. CONCLUSIONS: The tested Aconitum alkaloids significantly increased the expression of MRP2 and BCRP by activating the Nrf2-mediated signalling pathway and enhanced the efflux activity of MRP2. The potential for herb-herb interactions or HDIs exists when Aconitum species are co-administered with substrate drugs that are transported via MRP2 and BCRP. Therefore, the Aconitum alkaloids may be used as quality indicators for the herbs of Aconitum species.

Chemical UPLC-ESI-MS/MS profiling of aconitum alkaloids and their metabolites in rat plasma and urine after oral administration of Aconitum carmichaelii Debx. Root extract.

In this paper, an ultra high performance liquid chromatography tandem mass spectrometric (UPLC-ESI-MS/MS) method in positive ion mode was established to systematically identify and to compare the major aconitum alkaloids and their metabolites in rat plasma and urine after oral administration of Fuzi extract. A total twenty-nine components including twenty-five C19-diterpenoid alkaloids and four C20-diterpenoid alkaloids were identified in Fuzi extract. Thirteen of the parent components and five metabolites were detected in rat plasma and sixteen parent compounds and six metabolites in urine. These parent components found in rat plasma and urine were mainly C19-diterpenoid alkaloids. All of the metabolites in vivo were demethylated metabolites (phase I metabolites), which suggested that demethylation was the major metabolic pathway of aconitum alkaloids in vivo. A comparison of the parent components in rat plasma and urine revealed that 3-deoxyacontine was found in plasma but not in urine, while kalacolidine, senbusine and 16-ß-hydroxycardiopetaline existed in urine but not in plasma, which indicated that most alkaloids components were disposed and excreted in prototype form. This research provides some important information for further metabolic investigations of Fuzi in vivo.

Pharmacokinetic evaluation of Shenfu Injection in beagle dogs after intravenous drip administration.

Shenfu Injection (SFI) is a well-defined Chinese herbal formulation that is obtained from red ginseng and processed aconite root. The main active constituents in SFI are ginsenosides and aconitum alkaloids. In this work, ginsenosides (ginsenoside Rg1, ginsenoside Rb1 and ginsenoside Rc) and aconitum alkaloids (benzoylmesaconine and fuziline) were used as the index components to explore the pharmacokinetic behavior of SFI. A selective and sensitive HPLC-MS/MS method was developed for the quantification of ginsenosides and aconitum alkaloids in dog plasma and was used to characterize the pharmacokinetics of the five index components after intravenous drip of three different dosages of SFI in beagle dogs. The pharmacokinetic properties of the index components were linear over the dose range of 2-8 mL/kg.

Dynamic Variation Patterns of Aconitum Alkaloids in Daughter Root of Aconitum Carmichaelii (Fuzi) in the Decoction Process Based on the Content Changes of Nine Aconitum Alkaloids by HPLC- MS- MS.

The chemical components in the decoctions of Chinese herbal medicines are not always the same as those in the crude herbs because of the insolubility or instability of some compounds. In this work, a high-performance liquid chromatography (HPLC) coupled with electrospray ionization (ESI) tandem mass spectrometry method was developed to explore dynamic variation patterns of aconitum alkaloids in Fuzi during the process of decocting aconite root. The fragmentation patterns of aconitum alkaloids using ESI and collision-induced dissociation (CID) techniques were reported. This assay method was validated with respect to linearity (r(2) > 0.9950), precision, repeatability, and accuracy (recovery rate between 94.6 and 107.9%).The result showed that the amounts of aconitum alkaloids in the decoction at different boiling time varied significantly. In the decoction process，the diester- type alkaloids in crude aconite roots have transformed into Benzoylaconines or aconines.

Simultaneous determination of ten Aconitum alkaloids in rat tissues by UHPLC-MS/MS and its application to a tissue distribution study on the compatibility of Heishunpian and Fritillariae thunbergii Bulbus.

A rapid, sensitive and selective ultra-high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for simultaneous determination of ten Aconitum alkaloids in rat tissues. The tissue samples were prepared by a simple procedure protein precipitation with acetonitrile containing 0.1% acetic acid and separated on an Agilent XDB C18 column (4.6 mm×50mm, 1.8µm) using gradient elution with a mobile phase consisting of water and acetonitrile (both containing 0.1% formic acid) at a flow rate of 0.3mL/min. The quantitive determination was performed on an electrospray ionization (ESI) triple quadrupole tandem mass spectrometer using selective reaction monitoring (SRM) under positive ionization mode. The established method was fully validated according to the USA Food and Drug Administration (FDA) bioanalytical method validation guidance and the results demonstrated that the method was sensitive and selective with the lowest limits of quantification (LLOQ) at 0.025ng/mL in rat tissue homogenates. Meanwhile, the linearity, precision, accuracy, extraction recovery, matrix effect and stability were all within the required limits of biological sample analysis. After method validation, the validated method was successfully applied to the tissue distribution study on the compatibility of Heishunpian (HSP, the processed product of Aconitum carmichaelii Debx) and Fritillariae thunbergii Bulbus (Zhebeimu, ZBM). The results indicated that the distribution feature of monoester diterpenoid aconitines (MDAs), diester diterpenoid aconitines (DDAs) and non-ester alkaloids (NEAs) were inconsistency, and the compatibility of HSP and ZBM resulted in the distribution amount of DDAs increased in tissues. What's more, the results could provide the reliable basis for systematic research on the substance foundation of the compatibility of the herbal pair.

Sensitive determination of three aconitum alkaloids and their metabolites in human plasma by matrix solid-phase dispersion with vortex-assisted dispersive liquid-liquid microextraction and HPLC with diode array detection.

A simple and sensitive method for determination of three aconitum alkaloids and their metabolites in human plasma was developed using matrix solid-phase dispersion combined with vortex-assisted dispersive liquid-liquid microextraction and high-performance liquid chromatography with diode array detection. The plasma sample was directly purified by matrix solid-phase dispersion and the eluate obtained was concentrated and further clarified by vortex-assisted dispersive liquid-liquid microextraction. Some important parameters affecting the extraction efficiency, such as type and amount of dispersing sorbent, type and volume of elution solvent, type and volume of extraction solvent, salt concentration as well as sample solution pH, were investigated in detail. Under optimal conditions, the proposed method has good repeatability and reproducibility with intraday and interday relative standard deviations lower than 5.44 and 5.75%, respectively. The recoveries of the aconitum alkaloids ranged from 73.81 to 101.82%, and the detection limits were achieved within the range of 1.6-2.1 ng/mL. The proposed method offered the advantages of good applicability, sensitivity, simplicity, and feasibility, which makes it suitable for the determination of trace amounts of aconitum alkaloids in human plasma samples.

Aconitum Alkaloid Poisoning Because of Contamination of Herbs by Aconite Roots.

Aconitum alkaloid poisoning can occur after drinking decoction and soup made from non-toxic herbs contaminated by aconite roots. In the present review, the main objective is to describe the clinical features, investigations and possible sources of contamination. A combination of neurological, gastrointestinal and cardiovascular signs and symptoms was seen. Ventricular tachyarrhythmias could occur in 18% of subjects. Yunaconitine and crassicauline A, mainly found in certain aconite roots from Southwest China, are most commonly involved. Herbal residues and unused herbs should first be inspected for gross contamination. On-site inspection at the retailer should exclude accidental mix-up or cross-contamination when handling aconite roots. Samples of prescribed herbs are examined for gross contamination and analysed for the presence of Aconitum alkaloids. Samples of the implicated herb are also collected from the wholesaler for investigation. If post-import contamination is unlikely, the regulatory authorities of the exporting countries should be notified for follow-up actions. It is a challenging task to work out how non-toxic herbs become contaminated by aconite roots. The source control with good agricultural and collection practices and quality assurance must be enhanced.

Microcalorimetry studies of the antimicrobial actions of Aconitum alkaloids.

The metabolic activity of organisms can be measured by recording the heat output using microcalorimetry. In this paper, the total alkaloids in the traditional Chinese medicine Radix Aconiti Lateralis were extracted and applied to Escherichia coli and Staphylococcus aureus. The effect of alkaloids on bacteria growth was studied by microcalorimetry. The power-time curves were plotted with a thermal activity monitor (TAM) air isothermal microcalorimeter and parameters such as growth rate constant (µ), peak-time (Tm), inhibitory ratio (I), and enhancement ratio (E) were calculated. The relationships between the concentration of Aconitum alkaloids and µ of E. coli or S. aureus were discussed. The results showed that Aconitum alkaloids had little effect on E. coli and had a potentially inhibitory effect on the growth of S. aureus.

Incidence and Causes of Aconitum Alkaloid Poisoning in Hong Kong from 1989 to 2010.

Aconite roots contain Aconitum alkaloids, which are highly toxic cardiotoxins and neurotoxins. In this review, the main objective was to determine the incidence and causes of Aconitum alkaloid poisoning in Hong Kong between 1989 and 2010, based on six published reports from the territory-wide poison control units. In the New Territories East of Hong Kong, the incidence of aconite poisoning showed a sudden and sustained decrease from 0.60 (1989-1991) to 0.16 (1992-1993) and 0.17 (1996-1998) per 100 000 population, after publicity measures in late 1991 to promote awareness of the toxicity of aconite roots. In the whole of Hong Kong, the incidence of aconite poisoning was even lower in January 2000-June 2004 (0.03 per 100 000 population). However, aconite poisoning became more common again in April 2004-July 2009 and 2008-2010 (0.15 and 0.28 per 100 000 population). Overdoses and use of inadequately processed aconite roots were important causes. As from 2004 to 2009, 'hidden' aconite poisoning (toxicity caused by contaminants in other dispensed herbs) emerged as an important cause. It is important to continue the safety monitoring of potent herbs and the networking of poison control units. Further systematic studies would be required to identify the likely sources of contamination of herbs.